OE, GLIMPSES BENEATH THE WATERS, 



tlie dye, whicli is a liquid of a creamy thickness and 

 of pale, indistinct colour. But if it be painted in the 

 forms required, as a cipher, or any other ornament, 

 on linen, or any other textile fabric, with a camel' s- 

 hair pencil, and exposed to the air, it rapidly assumes 

 a yellow tone ; which first changes to green, then 

 blue, till at last it becomes a full strong indigo, 

 exhibiting plainly all the forms that have been 

 traced. A crimson-red change next ensues, and the 

 final colour, which is indelibly permanent, is a red- 

 dish purple. 



There is also a large naked Mollusc, one of the 

 Aplysia^ that pours forth, under excitement, a secre- 

 tion of rich purple hue ; but the colour is considered 

 valueless as a dye, from its extreme volatility, though 

 it is stated that it may be rendered permanent by 

 means of nitric acid. 



The common JPlanorbis corneus, a shell coiled in 

 the form of a ram's horn, has a similar property ; 

 but the colour of the fluid is still more volatile. 

 The purple liquid, however, contained in another of 

 our native shells (Scalaria) is very permanent. 



It is well known that the ink of the Chinese, 

 which we term Indian ink, is prepared from the 

 Cuttle, and the Cuttles of the Mediterranean Sea 

 furnished the principal black inks and dyes of the 



79 



